#10, 340 MacAlpine Crescent, Fort McMurray, AB T9H 4A8 T: F: thurber.ca. Attachment #1

Transcription

1 #10, 340 MacAlpine Crescent, Fort McMurray, AB T9H 4A8 T: F: thurber.ca Attachment #1

2 TABLE OF CONTENTS 1. INTRODUCTION BACKGROUND AND SCOPE OF WORK METHODOLOGY GEOLOGICAL SETTING General Surficial Geology Glaciofluvial Deposits Colluvium Deposits General Colluvium (Surficial Deposits) Colluvium (Clearwater Formation) Colluvium (McMurray Formation) Alluvium Deposits Bedrock Geology Valley Formation Valley Stability SITE RECONNAISSANCE PRELIMINARY ASSESSMENT General Slope Movement Hazards and Infrastructure PRELIMINARY RECOMMENDATIONS... 9 STATEMENT OF LIMITATIONS AND CONDITIONS APPENDIX A Drawing No Overall Site Plan Drawing No Surficial Geology Map Drawing No Cross-Section A-A Drawing No August 20, 2016 Aerial Photograph APPENDIX B Selected Photographs from the May 4, 2017 Site Visit

3 1. INTRODUCTION This report presents the results of a desktop slope stability study carried out by Thurber Engineering Ltd. (Thurber) for a portion of the Draper Area in Fort McMurray, Alberta. The overall scope of the slope stability study was discussed at a meeting on March 7, 2017 between Mr. Oscar Gonzalez, P.Eng. of the Regional Municipality of Wood Buffalo (Municipality) and Mr. John Rybak, P.Eng. of Thurber. Authorization to proceed with the work was received verbally from Mr. Gonzalez on or about March 16, It is a condition of this report that Thurber s performance of its professional services is subject to the attached Statement of Limitations and Conditions. 2. BACKGROUND AND SCOPE OF WORK Residential properties have been constructed on the Clearwater River valley slope surface within the Draper area of Fort McMurray. A few of the residents raised concerns to the Municipality about the stability of the slopes in this area. A geotechnical slope stability study was previously completed in this area by Terracon Geotechnique Ltd. in The results of the 1999 study were incorporated into the Highway 69/Clearwater Valley Area Structure Plan (ASP), Bylaw 99/058. This ASP has been used to provide guidelines for the development on the slopes of the Draper area. Thurber s scope of work was to undertake a geotechnical desktop study to summarize existing information and provide a preliminary high level assessment of the overall stability in this area. Thurber s scope of work did not include the following: Field investigation, including drilling test holes and/or the installation of geotechnical instrumentation instruments. Geotechnical assessments of individual privately owned lots. Recommendations to remediate or mitigate active landslides (if any). The boundaries of the study area are shown on Drawing No , included in Appendix A. Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 1 of 10

4 3. METHODOLOGY This study included the review of the following: LiDAR data flown in The LIDAR data was used to mark the top and the bottom of the valley slopes, observe and mark existing landforms and features, and create a cross section in the study area. The LIDAR data was used to prepare the site plan shown on Drawing No in Appendix A. Available surficial geology maps. The geology maps were used to prepare Drawing No in Appendix A. Aerial photography flown for the Municipality on August , which was viewed by Thurber through the Wood Buffalo Viewer retrieved from: The aerial photograph image is shown on Drawing No in Appendix A. A site reconnaissance of the area was also conducted on May 4, 2017 by Mr. John Rybak, and Dr. Tarek Abdelaziz, both P.Eng. of Thurber, who were accompanied by Mr. Oscar Gonzalez, P.Eng. of the Municipality. The aim of the site visit was to inspect accessible areas of potential instability noted from the LiDAR data, or areas of concern expressed by the Municipality or others. Select photographs taken during the site visit are included in Appendix B. 4. GEOLOGICAL SETTING 4.1 General The following references were used to create the overall geological profile at the study area: L.A. Bayrock and T.H.F. Reimchen. Surficial Geology Waterways. Alberta Geological Survey. Published L.D. Andriashek. E.J. Waters. Bedrock topography of the Waterways area, NTS 74D. Alberta Geological Survey. Published Alberta Energy Regulator/ Alberta Geological Survey. Bedrock Geology of Alberta. Map 600. Published Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 2 of 10

5 4.2 Surficial Geology Glaciofluvial, Colluvium, and Alluvium deposits are the major surficial units in the study area. These deposits are described briefly below and are shown on Drawing , included in Appendix A Glaciofluvial Deposits Glaciofluvial deposits are mainly located in the plateau areas behind the crest of the valley slopes. The glaciofluvial deposits typically consist of sand, gravel and clay and are underlain by the Clearwater Formation Colluvium Deposits General Colluvium deposits originate from erosion and landslide events occurring through surficial deposits and bedrock formations in the valley settings. In the study areas, colluvium deposits are located along the Clearwater River valley and Saprae Creek valley slopes (i.e. the slopes facing the Clearwater River and Saprae Creek respectively). The colluvium in the study area can be divided into three distinct units: Colluvium (Surficial Deposits) Colluvium (Clearwater Formation) Colluvium (McMurray Formation). The above-noted colluvium units are shown on Drawing No , included in Appendix A. Semi-active slopes in this area contain colluvium that is currently experiencing slow creep movements and/or Solifluction. Solifluction is a slow downslope movement of waterlogged soil in areas underlain by frozen ground that acts as a barrier to water percolation. Solifluction is initiated by frost action and augmented by meltwater resulting from alternate freezing and thawing of snow and ground ice. Slope failures due to Solifluction are typically abrupt and characterized by rapid movements. Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 3 of 10

6 Colluvium (Surficial Deposits) This colluvium unit originates from weathered surficial deposits (denoted in yellow on Drawing No ), and is composed of a mixture of sand, gravel, silt, and clay. The weathered surficial deposits moved down along the uppermost scarp in the Clearwater River Valley. Runoff eroded and washed the weathered and collapsed material down the valley slope. Slumping and rotational-type landslides are the common failure modes in this area Colluvium (Clearwater Formation) The colluvium derived from the Clearwater Formation (denoted in pink on Drawing No ) is formed from the exposed bedrock during the initial incision into the valley slope of the Clearwater River. The colluvium is composed of weathered and gravitationally moved Clearwater Formation clay shale and material washed out from the upper surficial colluvium unit. Large, massive inactive or semi-active historical landslides are typical in this area. The landslides are mostly rotational type and are formed within the bedrock and/or colluvium deposits. The clearwater colluvium is in a slow movement downslope primarily as seasonal creep movement and occasionally as solifluction or mudflow. Large scale and fast-moving landslides could have been activated in this unit due to the existing developments on the slope surface Colluvium (McMurray Formation) The McMurray colluvium (denoted by hatching on Drawing No ) is exposed at the bottom of the Clearwater River Valley. This colluvium unit originates from landslide debris moved down the slope surface from the upper landslide blocks (i.e. mainly from surficial and clearwater colluvium units) and/or from the erosion of the exposed weathered units of the McMurray Formation. The thickness of this colluvium unit can range from a few meters to more than tens of meters. This colluvium is mainly composed of clay, bedrock slabs, and silt with sand and gravel particles and is mostly saturated by groundwater and surface water. Groundwater discharged from upper layers (particularly from the surficial deposits, Wabiskaw Member and the Clearwater Formation) accumulate in the colluvium and discharge very slowly into alluvium deposits. Water Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 4 of 10

7 discharge is anticipated to be slow because of the low permeability of the colluvium and McMurray Formation deposits. The soil movement in this unit is predominately solifluction and creep with some active landslides. The toe of major solifluction lobes and sheets are shown on Drawing in Appendix A. Solifluction lobes and sheets are types of slope failures and landforms. In Solifluction lobes, sediments form a tongue-shaped feature due to differential downhill flow rates. On the other hand, Solifluction sheets sediment moves more-less uniformly downslope, being thus a less selective form of erosion than Solifluction lobes. The soil movement in the solifluction lobes and sheets are regulated by seasonal freeze and thaw. Development activities along the slope surface in this unit may have increased the rate of soil movement, resulting in the development of new landslides or reactivation of old landslides Alluvium Deposits Alluvium deposits, generally consisting of poorly to well-sorted, stratified to massive sand, gravel, silt, clay and organic sediments, are located along the flat bottoms (river bed and terraces) of the valleys where rivers are present. The alluvial deposits may contain boulders and cobbles and are occasionally mixed with colluvial deposits at the boundaries between the river terrace and the toe of the valley slopes. 4.2 Bedrock Geology The uppermost bedrock in most of the study area is the Clearwater Formation, which is underlain by the McMurray Formation. The Clearwater Formation consists mainly of extremely weak to weak (in rock terms), high plastic clay shale with occasional interbeds of weak to strong siltstone and sandstone. A layer of greenish extremely weak to weak, glauconitic sandstone (Wabiskaw Member) is typically present near the base of the Clearwater Formation. The McMurray Formation typically consists of interbedded oil impregnated sand, siltstone and clay shale. A layer of clean uniform sand ("water sand") containing saline water is sometimes present near the base of the McMurray Formation. Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 5 of 10

8 The Clearwater and McMurray formations are underlain by the Devonian Waterways Formation predominately composed of limestone, dolomite, and shale. The limestone ranges from weak clayey "argillaceous" limestone to moderately strong to very strong biomicritic limestone. Very weak, high plastic calcareous shale layers, are sometimes present interbedded within the limestone. A simplified Stratigraphic Cross-section A-A, along the Clearwater River valley, is presented on Drawing No in Appendix A. The cross section shows the limits of the various strata based on our interpretation of the slope conditions and previous experience in other projects within the study area. 4.3 Valley Formation At the completion of the last glaciation, the river/creek valleys in the study area were formed from a rapid meltwater discharge that carved the valleys out of the bedrock. The rapid down-cutting of the valleys led to the massive landslides whose scarps form the upper-most portion of the river/creek valleys. The ancient landslides appear to have been mainly based in the Clearwater Shale, which is relatively strong when confined by many meters of soil overburden, but weathers and weakens over time when exposed and unloaded in a valley setting, gradually reducing in strength to that of stiff, high plastic clay. 4.4 Valley Stability Weak clay colluvium (slide material), mainly derived from the Clearwater Formation clay shale but also including sand, clay till, and McMurray Formation materials, is draped over most of the present-day valley slopes in the study area. In early stages of the valley formation, as colluvium came down the slope, it would have been removed by river processes. However, in more recent geological time, as the rate of erosion decreased and the river moved away from the valley slopes and formed a terrace with alluvial deposits, at some locations in the valleys, the colluvium would have accumulated at the base of the valley slope and extended in a mantle up the valley slope, eventually reaching a meta-stable slope angle. The development of forests over the slopes would have helped protect the slope surface from erosion and reduced surface water infiltration to help maintain this quasistate of equilibrium. Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 6 of 10

9 5. SITE RECONNAISSANCE The following summarizes the limited observations made within the western half of the study area, where access to the slopes was granted by property owners. The bottom of the slope was bare of vegetation, particularly around existing developments. The slope area to the south of the developed areas was covered with a light to dense forest. Fast seepage from the hill side was noted at a few of the inspected locations. A few of the developed areas were surrounded by trench drains to divert groundwater seepage away from the developments. Deadfall and tilting trees, due to landslide activities, were noted within the forest above the developed areas. Fresh and old landslide cracks were noted within the forest above the developed areas. Existing retaining wall systems between the developed areas and the hill side were noted to have been shifted or failed. A well-defined local landslide was noted in the backyard of one of the existing properties. 6. PRELIMINARY ASSESSMENT 6.1 General The following provides our preliminary assessment based on the current level of investigation. The valley slope in the study area experienced extensive landslide activities in ancient times. At present, the valley slope appears to be mostly in a quasi-stable state (i.e. in equilibrium with a Factor of Safety of about 1.0) and is prone to slow creep movements, particularly in forested areas. Based on Thurber s experience elsewhere along the Clearwater River valley slope and in similar slowly creeping slopes in Fort McMurray, the movement rates could range from less than 5 mm per year to 10 mm per year. Most of the existing developments are located on the surface of the lower colluvium slope. The lower colluvium slope is saturated, very sensitive to ground disturbance (including but not limited to alteration of grades, drainage pattern, and deforestation). Disturbance to existing landslide block(s) could lead to accelerated movements and abrupt slope failures. Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 7 of 10

10 There are a few areas where the slopes appear to be moving at a high rate than creeping slopes (i.e. actively moving slopes). These areas are mainly located near the bottom of the valley slope, where developments took place in the lower colluvium unit. The approximate locations of potential active landslides, based on LiDAR data, are shown on Drawing No The information collected during this study indicates that the existing landslides within the valley slopes may have recently become more active than in previous years. It is impossible though to predict the exact reasons and timing for accelerated slope movements in the absence of a Geohazard Risk Management Program, which typically includes ongoing visual inspections and a semi-annual instrumentation monitoring program. In addition, some possible reasons for progressive acceleration of ancient landslides or the development of new landslides may include loss of vegetation due to the 2016 wildfire, heavy rainfall events in late 2016 saturating the ground or causing additional erosion, lot grading activities undertaken by residents or land owners (resulting in the disturbance of existing vegetation and increase in surface water infiltration and runoff, disturbance to weak sensitive colluvium deposits (through cuts and fills), and likely variation in groundwater levels), or just the natural cycle of slope movements Slope Movement Hazards and Infrastructure The following provides general comments regarding the impact of slope movement on infrastructure. Slope movements are hazardous to infrastructure such as houses, retaining walls, roads and underground utilities. The risks are typically high if the investment is located on or within a moving slope. Even though the movement of slowly creeping landslides appears to be relatively steady, the movement may be episodic with movement rates that could vary greatly over timescales (i.e. movement rates may increase or decrease significantly during a specific time period). Ongoing movements of landslides can create uneven settlements in structures that can lead to cracks in walls, uneven floors and loss of functionality. Accumulation in slope movements can lead to stretching and eventual breaks in buried utilities. Slope creep movements can also exert high pressures on retaining walls and if they are not designed to handle those loads can result in bowing and eventual failure of the walls. Slow slope Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 8 of 10

11 movements can result in cracking of pavement and dips/humps on the road (such as observed dips and humps at a few locations along Draper Road). If the slope movements continue to accelerate, they can lead to a landslide that seriously damages the infrastructure and potentially threatens the safety of the public. Infrastructure located at or near the crest or the toe of a moving slope can still be at risk for the following reasons: a) If a landslide is initiated or enlarged in the slope, the landslide cracks may extend beyond the crest into the plateau land behind the slope. b) If a landslide moves down the slope, the landslide debris may run out beyond the toe of the slope. c) If a landslide mass becomes saturated during a heavy rainfall event, the landslide debris may travel a significant distance past the toe of the slope in a rapid manner. 7. PRELIMINARY RECOMMENDATIONS Preliminary recommendations are provided below for slope stability management in this area. The slopes in this area are sensitive to disturbance, and hence any ground disturbance including but not limited to grading work (including drainage improvements), underground utility installation, temporary or permanent support system installation being done by contractors, homeowners, or others must be reviewed and approved by the Municipality prior to the start of the work. This is to ensure that any sort of ground disturbance activities do not pose a risk to the property on which the work is being done or to adjacent properties. Homeowners who believe that their properties are being affected by slope movements should retain a qualified geotechnical engineering firm, registered in the Province of Alberta, to address slope stability concerns; quantify potential risks of instability on existing property and adjacent properties; provide short and long-term mitigative measures; and assess whether a slope movement would constitute a safety concern. It is understood that the Municipality has a limited policy for development on or around valley slopes. It is recommended that the Municipality revises existing regulations or develops a new policy for the assessment, evaluation, prioritization, and mitigation of potential stability concerns of valley slopes and that provides development guidelines Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 9 of 10

12 when constructing near slopes. Similar polices has been developed in other jurisdictions such as the City of Edmonton and the City of Calgary. The Municipality should also consider implementing a Geohazard Risk Management Program to monitor Municipal lands and infrastructure for signs of damage caused by ongoing slope movements. Any development, or redevelopment, within the study area must retain a qualified geotechnical engineering firm, registered in the Province of Alberta, to: a) Assess whether the site is suitable for the proposed development from a slope stability perspective. b) Identify any hazardous conditions that may impact proposed development. c) Undertake a detailed quantitative (i.e. slope stability analysis) and qualitative slope stability assessments to evaluate a) the impact of construction on the stability of existing slopes and adjacent developments, b) the impact of any slope instability issues on the proposed development and public safety, and c) potential mitigative measures to protect public and infrastructure from any hazardous conditions. Client: Regional Municipality of Wood Buffalo Date: July 18, 2017 File: e-file: \\H\15359 rpt - FtMc Page: 10 of 10

13 STATEMENT OF LIMITATIONS AND CONDITIONS 1. STANDARD OF CARE This Report has been prepared in accordance with generally accepted engineering or environmental consulting practices in the applicable jurisdiction. No other warranty, expressed or implied, is intended or made. 2. COMPLETE REPORT All documents, records, data and files, whether electronic or otherwise, generated as part of this assignment are a part of the Report, which is of a summary nature and is not intended to stand alone without reference to the instructions given to Thurber by the Client, communications between Thurber and the Client, and any other reports, proposals or documents prepared by Thurber for the Client relative to the specific site described herein, all of which together constitute the Report. IN ORDER TO PROPERLY UNDERSTAND THE SUGGESTIONS, RECOMMENDATIONS AND OPINIONS EXPRESSED HEREIN, REFERENCE MUST BE MADE TO THE WHOLE OF THE REPORT. THURBER IS NOT RESPONSIBLE FOR USE BY ANY PARTY OF PORTIONS OF THE REPORT WITHOUT REFERENCE TO THE WHOLE REPORT. 3. BASIS OF REPORT The Report has been prepared for the specific site, development, design objectives and purposes that were described to Thurber by the Client. The applicability and reliability of any of the findings, recommendations, suggestions, or opinions expressed in the Report, subject to the limitations provided herein, are only valid to the extent that the Report expressly addresses proposed development, design objectives and purposes, and then only to the extent that there has been no material alteration to or variation from any of the said descriptions provided to Thurber, unless Thurber is specifically requested by the Client to review and revise the Report in light of such alteration or variation. 4. USE OF THE REPORT The information and opinions expressed in the Report, or any document forming part of the Report, are for the sole benefit of the Client. NO OTHER PARTY MAY USE OR RELY UPON THE REPORT OR ANY PORTION THEREOF WITHOUT THURBER S WRITTEN CONSENT AND SUCH USE SHALL BE ON SUCH TERMS AND CONDITIONS AS THURBER MAY EXPRESSLY APPROVE. Ownership in and copyright for the contents of the Report belong to Thurber. Any use which a third party makes of the Report, is the sole responsibility of such third party. Thurber accepts no responsibility whatsoever for damages suffered by any third party resulting from use of the Report without Thurber s express written permission. 5. INTERPRETATION OF THE REPORT a) Nature and Exactness of Soil and Contaminant Description: Classification and identification of soils, rocks, geological units, contaminant materials and quantities have been based on investigations performed in accordance with the standards set out in Paragraph 1. Classification and identification of these factors are judgmental in nature. Comprehensive sampling and testing programs implemented with the appropriate equipment by experienced personnel may fail to locate some conditions. All investigations utilizing the standards of Paragraph 1 will involve an inherent risk that some conditions will not be detected and all documents or records summarizing such investigations will be based on assumptions of what exists between the actual points sampled. Actual conditions may vary significantly between the points investigated and the Client and all other persons making use of such documents or records with our express written consent should be aware of this risk and the Report is delivered subject to the express condition that such risk is accepted by the Client and such other persons. Some conditions are subject to change over time and those making use of the Report should be aware of this possibility and understand that the Report only presents the conditions at the sampled points at the time of sampling. If special concerns exist, or the Client has special considerations or requirements, the Client should disclose them so that additional or special investigations may be undertaken which would not otherwise be within the scope of investigations made for the purposes of the Report. b) Reliance on Provided Information: The evaluation and conclusions contained in the Report have been prepared on the basis of conditions in evidence at the time of site inspections and on the basis of information provided to Thurber. Thurber has relied in good faith upon representations, information and instructions provided by the Client and others concerning the site. Accordingly, Thurber does not accept responsibility for any deficiency, misstatement or inaccuracy contained in the Report as a result of misstatements, omissions, misrepresentations, or fraudulent acts of the Client or other persons providing information relied on by Thurber. Thurber is entitled to rely on such representations, information and instructions and is not required to carry out investigations to determine the truth or accuracy of such representations, information and instructions. c) Design Services: The Report may form part of design and construction documents for information purposes even though it may have been issued prior to final design being completed. Thurber should be retained to review final design, project plans and related documents prior to construction to confirm that they are consistent with the intent of the Report. Any differences that may exist between the Report s recommendations and the final design detailed in the contract documents should be reported to Thurber immediately so that Thurber can address potential conflicts. d) Construction Services: During construction Thurber should be retained to provide field reviews. Field reviews consist of performing sufficient and timely observations of encountered conditions in order to confirm and document that the site conditions do not materially differ from those interpreted conditions considered in the preparation of the report. Adequate field reviews are necessary for Thurber to provide letters of assurance, in accordance with the requirements of many regulatory authorities. 6. RELEASE OF POLLUTANTS OR HAZARDOUS SUBSTANCES Geotechnical engineering and environmental consulting projects often have the potential to encounter pollutants or hazardous substances and the potential to cause the escape, release or dispersal of those substances. Thurber shall have no liability to the Client under any circumstances, for the escape, release or dispersal of pollutants or hazardous substances, unless such pollutants or hazardous substances have been specifically and accurately identified to Thurber by the Client prior to the commencement of Thurber s professional services. 7. INDEPENDENT JUDGEMENTS OF CLIENT The information, interpretations and conclusions in the Report are based on Thurber s interpretation of conditions revealed through limited investigation conducted within a defined scope of services. Thurber does not accept responsibility for independent conclusions, interpretations, interpolations and/or decisions of the Client, or others who may come into possession of the Report, or any part thereof, which may be based on information contained in the Report. This restriction of liability includes but is not limited to decisions made to develop, purchase or sell land. HKH/LG_Dec 2014

14 APPENDIX A Drawing No Overall Site Plan Drawing No Surficial Geology Map Drawing No Cross-Section A-A Drawing No August 20, 2016 Aerial Photograph

15 N A CLEA R R RIV ER CN RAIL W AY DRAPE E S R ROAD 250 W WATE 26 AE PR 0 SA CR EE K A' H:\15000\15359 P - Fort McMurray Slope Stability Study, Groundwater Study and Instrumentation Installation\Drafting\ ,3,4.dwg Jun. 05, R EGIONAL MUNICIPALITY OF LEGEND WOOD BUFFALO FORT McMURRAY SLOPE STABILITY STUDY DRAPER AREA GROUND SURFACE CONTOURS (CONTOUR INTERVAL: 2m) NOTE: THE GROUND SURFACE CONTOURS HAVE BEEN ESTIMATED FROM THE 2016 LIDAR DATA. SITE PLAN DWG No m DRAWN BY DESIGNED BY SCALE 1:7500 APPROVED BY SCALE DATE FILE No. ML MJB TSA 1:7500 JUNE

16 H:\15000\15359 P - Fort McMurray Slope Stability Study, Groundwater Study and Instrumentation Installation\Drafting\ dwg Jun. 05, N A CLEA R R RIV E S WATE W ER CN RAIL W AY DRAPE A' SA PR AE CR EE K R ROAD LEGEND R EGIONAL MUNICIPALITY OF ALLUVIUM: SAND AND GRAVEL WITH CLAY SEMI ACTIVE COLLUVIUM (MCMURRAY FORMATION): MIX OF SURFICIAL AND BEDROCK WEATHERED MATERIAL. CREEP AND SOLIFLUCTION LOBES AND SHEETS. SEMI ACTIVE COLLUVIUM (CLEARWATER FORMATION): WEATHERED CLEARWATER CLAYSHALE AND SOME WASHED OUT SURFICIAL DEPOSITS. ROTATIONAL LANDSLIDES AND CREEP. SEMI ACTIVE COLLUVIUM (SURFICIAL DEPOSITS): MIX OF SAND, GRAVEL, SILT AND CLAY. SLUMPS, ROTATIONAL LANDSLIDES AND CREEP. GLACIOFLUVIAL SAND AND GRAVEL OVERLYING GLACIAL TILL WOOD BUFFALO FORT McMURRAY SLOPE STABILITY STUDY DRAPER AREA ACTIVE LANDSLIDE MAJOR SOLIFLUCTION LOBES AND SHEETS SURFICIAL GEOLOGY MAP TOP OF VALLEY SLOPE BOTTOM OF VALLEY SLOPE NOTES: 1. EXTENT OF ACTIVE LANDSLIDES ARE APPROXIMATE. 2. THE MAP IS BASED ON THE 2016 LIDAR DATA AND THE FOLLOWING REFERENCE MAPS: a) L.A. BAYROCK AND T.H.F. REIMCHEN. SURFICIAL GEOLOGY WATERWAYS. ALBERTA GEOLOGICAL SURVEY. PUBLISHED b) L.D. ANDRIASHEK. E.J. WATERS. BEDROCK TOPOGRAPHY OF THE WATERWAYS AREA,NTS 74D. ALBERTA GEOLOGICAL SURVEY. PUBLISHED c) ALBERTA ENERGY REGULATOR/ ALBERTA GEOLOGICAL SURVEY. BEDROCK GEOLOGY OF ALBERTA. MAP 600. PUBLISHED SCALE 1: m DWG No DRAWN BY DESIGNED BY APPROVED BY SCALE DATE FILE No. ML MJB TSA 1:7500 MAY

17 H:\15000\15359 P - Fort McMurray Slope Stability Study, Groundwater Study and Instrumentation Installation\Drafting\ ,3,4.dwg Jun. 05, 2017 ELEVATION (m) A CLEARWATER RIVER CN RAILWAY DRAPER ROAD???????? GROUND SURFACE (2016 LIDAR DATA) ????????????????????????????????? DEVONIAN WATERWAYS FORMATION (CLAY SHALE AND LIMESTONE) DISTANCE (m)????????????????? CLEARWATER FORMATION (CLAY SHALE)???????????? McMURRAY FORMATION (OILSAND)????? A' ELEVATION (m) LEGEND ALLUVIUM DEPOSIT SEMI ACTIVE COLLUVIUM (MCMURRAY FORMATION): MIX OF SURFICIAL AND BEDROCK WEATHERED MATERIAL. CREEP AND SOLIFLUCTION LOBES AND SHEETS. SEMI ACTIVE COLLUVIUM (CLEARWATER FORMATION): WEATHERED CLEARWATER CLAYSHALE AND SOME WASHED OUT SURFICIAL DEPOSITS. ROTATIONAL LANDSLIDES AND CREEP. SEMI ACTIVE COLLUVIUM (SURFICIAL DEPOSITS): MIX OF SAND, GRAVEL, SILT AND CLAY. SLUMPS, ROTATIONAL LANDSLIDES AND CREEP. GLACIOFLUVIAL DEPOSIT NOTE: CROSS SECTION A - A' IS BASED ON THE 2016 LIDAR DATA AND AVAILABLE GEOLOGICAL INFORMATION IN THE STUDY AREA. DRAWN BY DESIGNED BY APPROVED BY SCALE DATE FILE No. FORT McMURRAY SLOPE STABILITY STUDY DRAPER AREA ML MJB TSA 1:3000 JUNE REGIONAL MUNICIPALITY OF WOOD BUFFALO CROSS SECTION A - A' DWG No

18 H:\15000\15359 P - Fort McMurray Slope Stability Study, Groundwater Study and Instrumentation Installation\Drafting\ ,3,4.dwg Jun. 05, 2017 CN RAILWAY DRAPER ROAD REGIONAL MUNICIPALITY OF WOOD BUFFALO FORT McMURRAY SLOPE STABILITY STUDY DRAPER AREA AUGUST 20, 2016 AERIAL PHOTOGRAPH DWG No DRAWN BY DESIGNED BY APPROVED BY SCALE DATE FILE No. ML TSA TSA N. T. S. JUNE

19 APPENDIX B Selected Photographs from the May 4, 2017 Site Visit

20 Photo 1: Large crack at the top of an active landslide behind one the existing properties to the south of Draper Road. Photo 2: Looking south at active local landslide behind a house

21 Photo 2a: Looking east at the toe of the landslide from Photo 2. The local landslide is toeing out very close to the property. It appears that the owner continued to excavate the toe of the landslide. Photo 3: Looking east at landslide from Photo 2

22 Photo 4: Large tension crack in the forested area behind one of the properties Photo 5: Head scarp crack of a landslide in the forested area

23 Photo 7: looking at a local landslide developing within a cut slope above the backyard of an existing property. The lock blocks were noted to be bulging. Photo 8: looking at the head scarp crack of the local landslide in Photo 7.

24 Photo 9: looking at an existing ramp to one of the properties located near the bottom of the slope. Seepage and surface runoff from the hill side continued to saturate the ramp. Photo 10: looking at a failed retaining wall behind one of the existing properties near the bottom of the slope.